sinster mark Grayson x fem!reader x main!mark grayson (just by the ending)

warnings: it’s a bit dark, a small mention of cannibalism but I promise nothing crazy, talks about death/killing, obsession, a bit of violence (choking), yandere?? if u can even call it that idk. uhh lmk if I missed anything ngl chat.

a/n: there’s not much about sinster mark tbh, he has such great writing potential tbh and I honesty just needed something to write or I was going to lose motivation 😞 also sinster mark and main!mark may be ooc..sorry

Mark.

Well… not her Mark.

But still—Mark.

He had Mark’s face. The same soft features she knew by heart, the same eyes she’d memorized, the same voice that had said her name a hundred different ways. And yet…

He wasn’t hers.

“…Still beautiful,” he said, his voice rougher—lower, edged with something that made her stomach twist.

Her breath caught.

Everything about him looked right… and wrong at the same time.

Same dark hair. Same height. Same build.

But the suit—yellow and black, sharper, harsher. A cape draped behind him like a shadow instead of a symbol. And his presence… it didn’t feel warm.

It felt heavy.

Dark.

Like standing too close to something dangerous.

“…Mark?” she asked, though the word came out unsure, almost fragile. His lips curved, but it wasn’t the smile she knew. Not soft, not awkward, not him. This one knew exactly what he was doing. “Not quite,” he replied, taking a slow step closer. Instinct told her to step back.

She didn’t.

Her feet felt rooted to the floor as her eyes scanned his face again, searching for something familiar, something hers. “I’ve seen you before,” he continued, tilting his head slightly, studying her like she was something interesting… something he’d been waiting to get his hands on. “Just… not like this.”

A chill ran down her spine.

“…Where is he?” she asked, forcing her voice to stay steady. “My Mark.” At that, his expression flickered—something unreadable passing through his eyes before it settled back into that same dark amusement. “Safe. For now,” he said simply.

That didn’t make her feel better.

He closed the distance between them, slow, deliberate, like he knew she wouldn’t run—even if she wanted to. “And you…” his gaze dragged over her, not shy, not gentle. “You’re exactly how I imagined.” Her heart pounded, a mix of fear and something she didn’t want to name. “You’re not him,” she said, more firmly this time, even as her voice wavered just slightly.

“I know,” he murmured.

His hand lifted, hesitating for just a second before brushing lightly against her jaw. The touch was familiar… but the intent behind it wasn’t.

That softness Mark had?

Gone.

Replaced with something sharper. Possessive. Curious in a way that made her pulse spike. “But you’re still looking at me like I am,” he added quietly. She swallowed hard, forcing herself to hold his gaze.

“…Because you look like him.”

His lips twitched.

“Careful,” he said, voice dropping. “That might make me want to keep you.”

The words hung in the air—dangerous, teasing, not entirely a joke. For the first time, she took a small step back. “…Try it,” she said, even though her heart was racing. That only seemed to amuse him more.“See?” he murmured, stepping forward again, closing the gap she tried to create. “He wouldn’t like that tone.”

A pause.

“…But I do.”

And that was the problem.

“I missed you,” he hummed, like it was something casual, like they were picking up a conversation instead of standing in the middle of something completely wrong.

Her stomach dropped.

“I killed you on my planet. World. Whatever.” He shrugged slightly, like the distinction didn’t matter, like that didn’t matter.

Then he stepped closer.

Slow.

Unhurried.

He circled her, boots quiet against the floor, cape brushing behind him like a shadow that refused to leave. “In my world,” he continued, voice thoughtful—almost nostalgic, “you were so different.” She didn’t move. Didn’t breathe. “Quiet. Shy. Soft-spoken.” His tone dipped, like he was remembering something fragile… before it twisted. “You barely looked at me.”

He stopped behind her.

Too close.

Here, it looks like you are all bite and bark.” A low chuckle slipped from him. “I could just eat you up.”

Her body went rigid.

Not because of the words—

But because of how he said them. There was no playfulness in it. No teasing. Just something dark. Something real. For a split second, her mind betrayed her, flashing something sharp and horrifying. Teeth. Blood. The way his voice dropped like he was picturing it, not joking about it. She swallowed hard, forcing herself to turn, even as every instinct screamed at her not to.

“…You’re sick,” she said, her voice quieter than she wanted—but steady enough.

His eyes met hers instantly.

And he smiled.

Not offended.

Not angry.

Interested.

“Maybe,” he said simply.

He stepped closer again, closing the small gap she’d created without even realizing it.

“But you’re still here.”

His gaze dragged over her face, searching, analyzing, like he was comparing her to the version he’d known. The version he’d killed.

“That one didn’t look at me like this,” he murmured.

Her hands curled slightly at her sides, heart pounding.

“…Like what?”

“Like you’re not afraid.”

A beat.

He tilted his head, studying her.

“…Even though you should be.”

Silence stretched between them, thick and suffocating. She forced herself to hold his gaze. “…Maybe I just don’t scare easy.”

That made something flicker in his expression, approval, maybe. Or amusement. “Good,” he said softly. His hand lifted again, slower this time, like he was testing her, giving her the chance to flinch.

She didn’t.

His fingers brushed her chin, tilting her face just slightly.

“Because I’d hate to break you too quickly.”

Her pulse spiked.

“…You already did,” she shot back, quieter now, but sharper. “In your world, remember?”

For a moment—

Just a moment—

Something shifted in his eyes.

Then it was gone.

Replaced with that same dark calm.

“…Yeah,” he said, almost under his breath. His grip didn’t tighten, but it didn’t leave either. “…And look how that turned out.”

A pause.

Then, softer, dangerously so:

“Maybe I’ll do it differently this time.”

Her heart dropped so fast it made her dizzy. She was going to move, she felt it, that instinct kicking in, muscles tensing, ready to step away, but his hand caught her waist first.

Hard.

It yanked her back against him before she could even think, her breath hitching as her back hit his chest. “I didn’t even get to finish what I wanted to do with you.” The words sank in slow. Heavy. Her pulse spiked, her hands hovering for a second like she didn’t know whether to push him away or brace herself.

“…Mark—” she started, but it came out thinner than she meant. “I wish I never killed you…” he murmured, and there was something off about it—not just regret, but obsession. Something that had festered. His face dipped into her neck, his breath warm against her skin, and she froze. “I think about it all the time…”

Her stomach twisted.

Not romantic.

Not soft.

Wrong.

“I could kill you now,” he continued, almost thoughtfully, like he was weighing options in his head. “Or take you with me…” His grip on her waist tightened—possessive, unyielding.“Lock you up so you can notice me this time. Love me this time.”

For a second—

just one—

fear locked her in place.

Because he didn’t sound like he was joking. He sounded like he’d already decided. Her throat went dry, but something in her snapped back into place anyway, that same bite he’d pointed out earlier. Her hand shot down, grabbing his wrist, not to pry it off, but to ground herself. “…You think locking me up would make me love you?” she said, voice low, steadier than she felt.

A pause.

She forced herself to turn her head just enough to look at him over her shoulder. “That version of me you killed?” she added quietly. “She wasn’t in love with you either, was she?”

Silence.

Not long—but enough.

His grip didn’t loosen.

But something in his expression shifted—just slightly. She swallowed, pushing just a little against his hold, not enough to break free, but enough to show she wasn’t just going to stand there and take it. “You didn’t lose me because you killed me,” she continued, softer now, but sharper. “You lost me because you never had me.”

That hit.

She felt it in the way his hand stilled for half a second.

His breath against her neck paused.

The air changed.

Dangerous in a different way now.

Slowly, he lifted his head.

“…You talk too much,” he murmured, but it lacked the earlier ease.

She let out a shaky breath, forcing a small, defiant huff.

“…And you don’t think enough.”

That earned her a quiet, almost disbelieving exhale from him, something between a laugh and something darker.

For a moment, it felt like standing on the edge of something..

like one wrong move could tip everything.

And she had no idea which way he’d fall.

He moved fast.

Too fast.

One second she was holding her ground, next, she was spun around, her back hitting something solid as his hand came up to her neck. Rough. Firm enough to steal the air from her lungs in a sharp gasp.

“Mark—“

His grip tightened, just enough to remind her he could do more.

“I like you,” he said, voice low, almost thoughtful, like he was discovering it in real time. “You don’t shy away.” Her hands came up instinctively, gripping his wrist, not quite pushing, not quite yielding. “You’re scared,” he continued, tilting his head slightly as he looked down at her, studying every reaction. “And yet… you’ve got that mouth on you.” His free hand came up, thumb brushing slowly across her bottom lip, dragging it down just slightly. Not gentle. Not kind.

Her breath hitched again, but her eyes stayed on his.

“I wonder…” he murmured, gaze flickering over her face, then lower, lingering in a way that made her stomach twist. “If your Mark even appreciates you the way I would.” A quiet, humorless chuckle slipped from him.

“I doubt it.”

Her fingers tightened around his wrist.

“You don’t know him,” she shot back, breath uneven, but defiant.

That earned her a small pause.

Then his eyes darkened, just a fraction.

“No,” he admitted. “But I know me.”

His hand at her neck shifted slightly, not squeezing harder, but not letting go either.

“And I know,” he continued, voice dropping, “that I wouldn’t let something like you go to waste.”

Her jaw clenched.

“I’m not something to have,” she said, sharper now, even as her pulse hammered against his grip.

That made him smile.

Slow.

Dangerous.

“No,” he said quietly. “Not yet.”

His thumb brushed her lip again, almost absentmindedly.

“But I could fix that.”

A beat.

“I’d have to break that pretty little attitude first.”

The words hung heavy between them.

For a split second, silence stretched—thick, suffocating.

Then—

She laughed.

Soft. Breathless. A little unsteady, but real.

“…You really think breaking me would make me yours?” she asked, tilting her head just slightly despite his hold.

That wasn’t fear in her eyes now.

Not fully.

Something sharper.

“That’s the difference between you and him,” she added, quieter. “He doesn’t need to break me.”

That hit.

Not loud.

Not explosive.

But enough.

His smile didn’t disappear

…but it changed.

And for the first time, there was something else in his gaze.

Not just control.

Not just amusement.

Something closer to tension.

Like she’d just made things a lot more complicated.

“I should kill you, bitch,” he growled, the words low and sharp as his face moved closer, too close. Her breath caught. For a second, she thought—this is it.

But then—

He stopped.

Completely.

Like something snapped.

His grip didn’t tighten, didn’t loosen—he just… froze. And then, slowly, a chuckle slipped from his lips. Low. Amused. Like he’d just remembered something funny. “…We can chat later.” And just like that. He was gone. No warning. No sound. No trace. Just..

Gone.

The silence that followed was deafening.

Her body stayed locked in place for a moment, like it hadn’t caught up yet. Then it hit her all at once. A shaky breath tore from her lungs. Then another. Her legs gave out, her back hitting the wall as she slid down, hands trembling as they came up to her face. She wasn’t going to break in front of him. She refused to.

But now—

Now he was gone.

A choked sob slipped out before she could stop it, her shoulders shaking as everything she held back came rushing in at once.

Her chest hurt.

Her throat burned.

And then—

“Baby…?”

Her head snapped up.

That voice—

Soft.

Familiar.

Him.

Her Mark.

She felt it instantly, the difference. The air didn’t feel heavy anymore. It didn’t feel suffocating. It felt… safe.

He was already moving, already pulling his mask off as he dropped to his knees in front of her. “Hey.. hey, I’m here,” he said quickly, his hands coming up to cup her cheeks, gentle, so gentle it almost broke her all over again. “Are you okay? Did he…did he hurt you?” His thumbs brushed under her eyes, wiping away tears she hadn’t even realized were falling that fast. She stared at him for a second, like she needed to be sure.

Same face.

Same eyes.

But this time—

Warm.

Panicked.

Hers.

“…Mark…” her voice cracked, and that was all it took. She leaned forward, grabbing onto him, burying her face into his shoulder as another sob broke free. He held her immediately, arms wrapping around her tight, one hand coming up to cradle the back of her head. “I’ve got you,” he murmured, over and over, like he needed her to hear it. “I’ve got you, I’m here, you’re okay…” Her fingers clutched at his suit, grounding herself in him, in the familiar feel, the steady way he held her, nothing like the other one.

“He—he said—” she tried, but her voice broke again.

Mark pulled back just enough to look at her, his hands still on her face, eyes scanning her for any sign of injury. “I know,” he said softly, even if he didn’t fully. “You don’t have to say it right now. You’re safe, okay? I’m right here.” His forehead pressed against hers, his breathing uneven—but controlled, like he was holding himself together for her.

“I’m not letting anything happen to you,” he added, quieter now, more certain. Her hands came up, gripping his wrists, anchoring herself to him.

“…That wasn’t you,” she whispered, like she needed to say it out loud.

Mark’s expression tightened for a second—but he nodded.

“I know,” he said.

And then, softer—